24-12-2012, 04:30 PM
(Seda postitust muudeti viimati: 24-12-2012, 04:34 PM ja muutjaks oli itbilen.)
Päris sama ei ole, see nagu tavaline bensiin, tabelid ainult rikkamad. Vaja siis mootorijuhtimist mis suudaks aru saada mis soontes voolab ja siis vastava lylituse teha...
On E85 you can use much richer mixtures when aiming for very high power. One of the advantages of E85 is the cooling properties since a lot more is injected. Because of that, you can run a much more advanced ignition setting.
Since the octane number is higher, you can also run a much more advanced ignition setting.
And the car will also develop more power because E85 will contain more energy at the same Lambda.
Why stock engine management systems can't adapt to E85:
Even if the stock engine management systems had bigger injectors to be able to run E85, they would never pull it off in a safe way, and this is why...
Any modern EFI can, and if you let it, it will adapt to any fuel regardless of what AFR it takes to reach Lambda=1. But they are not programmed that way.
You can extremely easy program it do run on gas, then on E85 without even doing anything else than just filling up with E85 at the pump. The programming is the easy bit. The EFI just reads the O2-sensor and corrects the base fuel mixture and stores how much is needed to get to Lambda=1. Then it uses that base line to run the fuel in question, whichever fuel it may be.
But... all modern EFI's have a built-in adaptation already. Not as big as the step between gas and E85, but big enough to fix the car if any error with the fueling should occur.
What that means when it comes to practical use is this: An EFI that is suppose to be fail safe, and at the same time have the possibility of running another fuel type, can not operate if something goes wrong in the system. It can not differentiate between a fault and a different fuel.
We could easily instruct both LH, Motronic, Megasquirt or any other self-learning computer to do this, but they would never be fail-safe. They would simply have a too big span in fuel adaptation (fuel-trim) that the car would break very easy if something went wrong.
Example 1: On a normal car when an injector only can spray half of its rated capacity, the O2-sensor picks this up and instructs the ECU to increase the fueling. Since it is increasing the fueling much more than it is suppose to in order to get to the right mixture again, it thinks that something is wrong, goes into limp-home mode and lights the CEL.
Example 2: On a car with a great span in adaptability, this would instead be interpreted as a different fuel, ultimately creating a dangerous situation for the engine, never goes into limp-home mode, and it also never tells the driver that something is wrong.
That is why there are no cars with this kind of adaptive EFI.
Other kinds of EFI systems exists though, like the SAAB Trionic system in the bio-power cars (and the GM system of course), or the Volvo system in the flexi-fuel cars. They do it differently. They have a sensor in the fuel line that tells the EFI what fuel is being used. Then the EFI switches tables in the computer.
Edit: aga 300kw- le saaks lisa kyll, tublisti kohe. Ökonoomsusest selle auto puhul nagunii ei saa rääkida
Tegelt v6iks keegi rääkida siin natuke E85-le konverteerimisest.V6i lausa eraldi teema v6iks sellest teha.
Praegu see muidugi nii huvitav ei ole aga kui varsti juba igayks biokytust toota suudab, kyll siis hinnad ka langevad veel.
On E85 you can use much richer mixtures when aiming for very high power. One of the advantages of E85 is the cooling properties since a lot more is injected. Because of that, you can run a much more advanced ignition setting.
Since the octane number is higher, you can also run a much more advanced ignition setting.
And the car will also develop more power because E85 will contain more energy at the same Lambda.
Why stock engine management systems can't adapt to E85:
Even if the stock engine management systems had bigger injectors to be able to run E85, they would never pull it off in a safe way, and this is why...
Any modern EFI can, and if you let it, it will adapt to any fuel regardless of what AFR it takes to reach Lambda=1. But they are not programmed that way.
You can extremely easy program it do run on gas, then on E85 without even doing anything else than just filling up with E85 at the pump. The programming is the easy bit. The EFI just reads the O2-sensor and corrects the base fuel mixture and stores how much is needed to get to Lambda=1. Then it uses that base line to run the fuel in question, whichever fuel it may be.
But... all modern EFI's have a built-in adaptation already. Not as big as the step between gas and E85, but big enough to fix the car if any error with the fueling should occur.
What that means when it comes to practical use is this: An EFI that is suppose to be fail safe, and at the same time have the possibility of running another fuel type, can not operate if something goes wrong in the system. It can not differentiate between a fault and a different fuel.
We could easily instruct both LH, Motronic, Megasquirt or any other self-learning computer to do this, but they would never be fail-safe. They would simply have a too big span in fuel adaptation (fuel-trim) that the car would break very easy if something went wrong.
Example 1: On a normal car when an injector only can spray half of its rated capacity, the O2-sensor picks this up and instructs the ECU to increase the fueling. Since it is increasing the fueling much more than it is suppose to in order to get to the right mixture again, it thinks that something is wrong, goes into limp-home mode and lights the CEL.
Example 2: On a car with a great span in adaptability, this would instead be interpreted as a different fuel, ultimately creating a dangerous situation for the engine, never goes into limp-home mode, and it also never tells the driver that something is wrong.
That is why there are no cars with this kind of adaptive EFI.
Other kinds of EFI systems exists though, like the SAAB Trionic system in the bio-power cars (and the GM system of course), or the Volvo system in the flexi-fuel cars. They do it differently. They have a sensor in the fuel line that tells the EFI what fuel is being used. Then the EFI switches tables in the computer.
Edit: aga 300kw- le saaks lisa kyll, tublisti kohe. Ökonoomsusest selle auto puhul nagunii ei saa rääkida
Tegelt v6iks keegi rääkida siin natuke E85-le konverteerimisest.V6i lausa eraldi teema v6iks sellest teha.
Praegu see muidugi nii huvitav ei ole aga kui varsti juba igayks biokytust toota suudab, kyll siis hinnad ka langevad veel.
having trouble having fun...